Therapeutic effect of Xuebijing combined with thymosin on hemorrhagic fever with renal syndrome: A protocol of systematic review and meta-analysis

BACKGROUND

The goal of this study is to assess the therapeutic effect of Xuebijing combined with thymosin (XBJ-T) for the treatment of patients with hemorrhagic fever with renal syndrome (HFRS).

METHODS

We will search the electronic databases of Cochrane Library, PUBMED, EMBASE, PsycINFO, Scopus, Opengrey, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Google scholar, Allied and Complementary Medicine Database, and Chinese Biomedical Literature Database from inception to the present. No language and publication status will be employed in this study. Based on the predefined eligibility criteria, selection of study and data extraction will be performed by 2 researchers independently. Study quality will be assessed using Cochrane risk of bias tool. We will apply RevMan 5.3 software to pool and analyze the extracted data.

RESULTS

This study will assess the therapeutic effect of XBJ-T for the treatment of patients with HFRS.

CONCLUSION

The findings of this study may provide systematic evidence to judge whether XBJ-T is an effective and safety intervention for HFRS.

STUDY REGISTRATION NUMBER

INPLASY202040068.

Experimental evidence for the involvement of F0/F1 ATPase and subsequent P2Y12 receptor activation in prothymosin alpha-induced protection of retinal ischemic damage

The inhibition of retinal ischemia-induced damage by post-ischemic prothymosin alpha (ProTα) was not affected in toll-like receptor 4 knockout (TLR4^-/-) mice but blocked by the pretreatment with antibody against F₀/F₁ ATPase α- or β-subunit, novel candidate for ProTα-receptor. In addition to the previous observation of ProTα-induced ATP release from cells, the present study showed a ProTα-induced enhancement of ATP hydrolysis activity of recombinant ATP5A1/5B complex. As the protection of retinal function by post-ischemic ProTα was abolished by anti-P2Y₁₂ antibody, the activation of F₀/F₁ ATPase and subsequent P2Y₁₂ receptor system may play roles in beneficial actions by post-ischemic ProTα.

No effect of thymosin beta-4 on the expression of the transcription factor Islet-1 in the adult murine heart

The transcription factor Islet-1 marks a progenitor cell population of the second heart field during cardiogenesis. In the adult heart Islet-1 expression is limited to the sinoatrial node, the ventricular outflow tract, and parasympathetic ganglia. The regenerative effect in the injured mouse ventricle of thymosin beta-4 (TB4), a 43-aminoacid peptide, was associated with increased Islet-1 immunostaining, suggesting the induction of an Islet-1-positive progenitor state by TB4. Here we aimed to reassess this effect in a genetic model. Mice from the reporter mouse line Isl1-nLacZ were primed with TB4 and subsequently underwent myocardial infarction. Islet-1 expression was assessed 2, 7, and 14 days after infarction. We detected only a single Islet-1+ cell in 8 TB4 treated and infarcted hearts which located outside of the sinoatrial node, the outflow tract or cardiac ganglia (in ~2500 sections). Two cells were identified in 5 control infarcted hearts. TB4 did not induce LacZ positivity in ventricular explants cultures of Isl1-nLacZ mice nor did it affect the density of LacZ+ cells in explant cultures of nLacZ+ regions of the heart. In summary, we found no evidence that TB4 reactivates Islet-1 expression in adult mouse ventricle.

Local Excision of Retinal Metastasis from Cutaneous Melanoma

The incidence of cutaneous melanoma is constantly rising. Ocular involvement is rare and the choroid is the most accessible structure to metastatic emboli.

The case described is noteworthy on account of several particular features:

1) the missed diagnosis of the primary malignancy. This might be because either cutaneous melanoma or cutaneous nevi show several common features;

2) the rarity of the retinal metastatic site. Unlike the choroid, the retina is an unusual metastatic site but, regardless of organ blood flow, the metastatic efficiency may be related to interactions between tumour cells and host tissue;

3) the treatment of the retinal metastasis, excised conservatively. As far as we know, this is the first report of a retinal metastasis being treated by local resection.

Thymosin β4 alleviates renal fibrosis and tubular cell apoptosis through TGF-β pathway inhibition in UUO rat models

BACKGROUND

Thymosin β4 (Tβ4) is closely associated with the cytoskeleton, inflammation, wound healing, angiogenesis, apoptosis, and myocardial regeneration, but the effects of Tβ4 treatment on chronic renal tubular interstitial fibrosis (CRTIF) are poorly known. This study aimed to examine the effects of Tβ4 on the renal apoptosis and the expression of transforming growth factor (TGF-β), E-cadherin, and α-smooth muscle actin (α-SMA) in CRTIF rat models.

METHODS

Male SD rats were randomized into four groups (sham group, unilateral ureteral obstruction (UUO) group, UUO + low-dose Tβ4 group, and UUO + high-dose Tβ4 group). The pathological changes of kidney tissue and its function were assessed two weeks after UUO. In renal interstitial tissue,TGF-β, E-cadherin and α-SMA expression was detected by western blot. In tubular epithelial cells, E-cadherin and α-SMA expression was detected using Real-time qPCR and western blot. Cell apoptosis of rat renal interstitial tissue and tubular epithelial cells was evaluated by immunofluorescence and western blot.

RESULTS

Two weeks after UUO, no differences in blood urea nitrogen and creatinine were observed between the four groups (P > 0.05). Compared to the UUO group, Tβ4 treatment decreased the 24-h proteinuria (P < 0.001) and reduced the area of pathological change (P < 0.01); this effect was more apparent in the UUO + high-dose Tβ4 group. Compared to the UUO group, a significant decrease in TGF-β and α-SMA protein expression was observed in the high-dose Tβ4 group. The level of E-cadherin protein was lower in the UUO group than the Tβ4 groups, and high-dose Tβ4 treatment further increased E-cadherin expression and improved cell apoptosis in the renal interstitial tissue. Analysis of in vitro tubular epithelial cells showed that α-SMA mRNA and protein expression decreased, while E-cadherin mRNA and protein expression increased by Tβ4 treatment. Similarly, these changes were more significant in the UUO + high-dose Tβ4 group. Tβ4 treatment improved the apoptosis of In vitro tubular epithelial cells compared with pure TGF-β stimulation, and equally, the decrease of apoptosis was more apparent in the TGF-β + high-dose Tβ4 group.

CONCLUSIONS

Tβ4 treatment might alleviate the renal fibrosis and apoptosis of tubular epithelial cells through TGF-β pathway inhibition in UUO rats with CRTIF.

Thymalfasin, a promising adjuvant therapy in small hepatocellular carcinoma after liver resection

There is limited information available concerning the effect of thymalfasin (Tα1) as an adjuvant therapy in hepatocellular carcinoma (HCC) patient who received liver resection. The present study aimed to evaluate whether Tα1 can improve the prognosis of small HCC patients after liver resection.A total of 206 patients with small HCC who underwent liver resection were analyzed in our retrospective cohort study. Patients were divided into 2 groups: group A (resection + Tα1, n = 44) and group B (resection, n = 162). Clinical data, overall survival (OS), and recurrence-free survival (RFS) were compared. Prognostic factors were identified using multivariate analysis.After a median follow-up of 47.0 months, 134 patients (65%) had recurrence, and 62 patients (30.09%) died. The 1, 3, and 5-year OS rate of patients in group A was 97.7%, 90.6%, and 82.9%, respectively, and 95.1%, 80.5%, and 62.9%, respectively, for patients in group B (P = .014). The 1, 3, and 5-year RFS rate of patients in group A was 70.5%, 56.8%, and 53.3%, respectively, and 65.8%, 41.3%, and 32.1%, respectively, for patients in group B (P = .015). Multivariate analysis indicated that Tα1 was an independent prognostic factor for both OS (P = .015, hazard ratio 0.349, 95% confidence interval 0.149-0.816) and RFS (P = .019, hazard ratio 0.564, 95% confidence interval 0.349-0.910).Tα1 as an adjuvant therapy after liver resection may improve the prognosis of small HCC patients after liver resection.

A Tobacco-Derived Thymosin β4 Concatemer Promotes Cell Proliferation and Wound Healing in Mice

Thymosin β4 (Tβ4) is a peptide that is known to play important roles in protection, regeneration, and remodeling of injured tissues in humans, and that shows great promise in a range of clinical applications. However, current strategies to Tβ4 are insufficient to meet growing demand and have a number of limitations. In this current study we investigated whether expression of recombinant Tβ4 in plants, specifically in tobacco (Nicotiana tabacum) leaves, represents an effective approach. To address this question, a 168 bp Tβ4 gene optimized for tobacco codon usage bias was constitutively expressed in tobacco as a 4-unit repeat concatemer, fused to a polyhistidine tag. Quantitative polymerase chain reaction and Western blot analyses were used to verify 4×Tβ4 expression in 14 transgenic tobacco lines and enzyme-linked immunosorbent assay analysis indicated 4×Tβ4 protein concentrations as high as 3 μg/g of fresh weight in the leaves. We observed that direct administration of tobacco-derived Tβ4 was more effective than Tβ4 either obtained commercially or derived from expression in Escherichia coli at promoting splenocyte proliferation in vitro and wound healing in mice through an endothelial migration assay. This study provides new insights into the development of plant-derived therapeutic proteins and their application by direct administration.

Impact of the immunomodulating peptide thymosin alpha 1 on multiple myeloma and immune recovery after hematopoietic stem cell transplantation

Multiple myeloma (MM) is characterized by the accumulation of monoclonal plasma cells in the bone marrow and causes several immune alterations in patients. Thymosin α1 (Tα1) is a thymic peptide that has been associated with immuno-stimulating properties. In addition, this peptide exerts anti-tumor effects in several cancer types. Beneficial effects of Tα1 administration have also been shown on immune reconstitution after hematopoietic stem cell transplantation (HSCT), a current treatment modality in hematological malignancies including MM. In this study, we observed a slight reduction in the proliferation of murine and human MM cell lines in the presence of Tα1 in vitro. However, using two immunocompetent murine MM models (5TGM1 and MOPC315.BM), we did not observe any impact of Tα1 administration on MM development in vivo. Furthermore, no beneficial effects of Tα1 treatment were observed on lymphocyte immune reconstitution after transfusion of human hematopoietic stem cells into immunodeficient mice. In conclusion, despite direct effects of Tα1 on human MM cell line proliferation in vitro, Tα1 did not exert anti-myeloma effects in vivo in the two murine models tested. Moreover, Tα1 failed to improve immune recovery in a xenogeneic HSCT model.

[Triplet anti-tumor therapy based on thymosin α-1 attenuates incidence of hepatoma and serum alpha-fetoprotein level in rat hepatoma model]

OBJECTIVE

To explore the impact of triple anti-tumor therapy based on thymosin α1 (Tα1) combined with Huaier granule(HG) and sirolimus on the level of serum alpha-fetoprotein (AFP) in rat models of liver cancer.

METHODS

Ninety Sprague-Dawley rats were randomly divided into triple anti-tumor therapy group, Tα1 group, HG group, sirolimus group, positive control and blank control groups, with 15 rats in each group. Except the blank control group, the rats in the other groups were induced using diethylnitrosamine (DEN) to establish liver cancer models. After DEN treatment, the triple therapy group underwent 0.8 mg/kg Tα1 subcutaneous injection (from once a day for two weeks to twice a week since the third week), 0.35 g/kg HG gavage (three times a day) and 1 mg/kg sirolimus gavage (once a day). The dose of the rest single drug groups were the same with that of the triple therapy group. The positive control and blank control groups were not treated with the drugs. The treatment lasted 20 weeks. Then, the behavior of the rats were observed at the different time points, and the level of serum AFP in the rats were detected at 6, 16, 18, 20 weeks, respectively.

RESULTS

The typical symptoms of liver cancer were seen in the DEN-induced rats at 16 weeks. Since the tenth week, 6 rats died one after another. Pathological section of rat liver tissue suggested that the rat models were established successfully. According to the incidence rate of liver cancer and the survival rate at 20 weeks, the triple anti-tumor therapy was significantly superior to the single drug treatments. In addition, the triple anti-tumor therapy significantly reduced the level of serum AFP in the rats.

CONCLUSION

The triple anti-tumor therapy can significantly prolong the survival time of rats with liver cancer, decrease the cancer incidence rate and the level of serum AFP.

Thymosin Beta 4 protects mice from monocrotaline-induced pulmonary hypertension and right ventricular hypertrophy

Pulmonary hypertension (PH) is a progressive vascular disease of pulmonary arteries that impedes ejection of blood by the right ventricle. As a result there is an increase in pulmonary vascular resistance and pulmonary arterial pressure causing right ventricular hypertrophy (RVH) and RV failure. The pathology of PAH involves vascular cell remodeling including pulmonary arterial endothelial cell (PAEC) dysfunction and pulmonary arterial smooth muscle cell (PASMC) proliferation. Current therapies are limited to reverse the vascular remodeling. Investigating a key molecule is required for development of new therapeutic intervention. Thymosin beta-4 (Tβ4) is a ubiquitous G-actin sequestering protein with diverse biological function and promotes wound healing and modulates inflammatory responses. However, it remains unknown whether Tβ4 has any protective role in PH. The purpose of this study is to evaluate the whether Tβ4 can be used as a vascular-protective agent. In monocrotaline (MCT)-induced PH mouse model, we showed that mice treated with Tβ4 significantly attenuated the systolic pressure and RVH, compared to the MCT treated mice. Our data revealed for the first time that Tβ4 selectively targets Notch3-Col 3A-CTGF gene axis in preventing MCT-induced PH and RVH. Our study may provide pre-clinical evidence for Tβ4 and may consider as vasculo-protective agent for the treatment of PH induced RVH.

[Impact of thymosin-alpha1 on reproduction of herpes simplex virus in cell system and on course of acute experimental infection in mice]

The article contains results of laboratory and experimental investigation carried out for comparative estimation of antiviral activity of thymosin-alpha1 (Ta1) against herpes simplex virus (HSV). It was demonstrated that administration of tymosin-alpha1 in cultivated in vitro cellular system had been inoculated with HSV provided inhibition of HSV reproduction and defense of cells of HSV cytopathogenic action. Moreover Ta1 ability to inhibit HSV reproduction in cell was comparable with the same ability of human alpha-interferon. Besides it was demonstrated that Ta1 parenteral administration to mice infected with HSV leaded to reduce of mice morbidity percent and prolonged of their survival rate. Ta1 ability to depress experimental viral infection development was higher than same ability of acyclovir.

Controlled release of thymosin β4 from injected collagen-chitosan hydrogels promotes angiogenesis and prevents tissue loss after myocardial infarction

AIMS

Acute myocardial infarction (MI) leads to fibrosis and severe left ventricular wall thinning. Enhancing vascularization within the infarct reduces cell death and maintains a thick left ventricular wall, which is essential for proper cardiac function. Here, we evaluated the controlled delivery of thymosin β4 (Tβ4), which supports cardiomyocyte survival by inducing vascularization and upregulating Akt activity, in the treatment of MI.

MATERIALS & METHODS

We injected collagen-chitosan hydrogel with controlled release of Tβ4 into the infarct after performing left anterior descending artery ligation in rats.

RESULTS

Tβ4-encapsulated hydrogel (thymosin) significantly reduced tissue loss post-MI (13 ± 4%), compared with 58 ± 3% and 30 ± 8% tissue loss for no treatment (MI only) and Tβ4-free hydrogel (control). Significantly more Factor VIII-positive blood vessels with diameter >50 µm were in the thymosin group compared with both MI only and control (p < 0.0001), showing Tβ4-induced vascularization. Wall thickness was positively correlated with the mature blood vessel density (r = 0.9319; p < 0.0001).

CONCLUSION

Controlled release of Tβ4 within the infarct enhances angiogenesis and presence of cardiomyocytes that are necessary for cardiac repair.

Controlled release of thymosin β4 using collagen-chitosan composite hydrogels promotes epicardial cell migration and angiogenesis

Rapid vascularization at the infarcted site is crucial for cardiac repair following myocardial infarction. Thymosin β4 (Tβ4), a 43-amino acid peptide, is both angiogenic and cardioprotective. Tβ4 in soluble form was previously shown to promote cell migration from quiescent adult cardiac explants. Here we developed a collagen-chitosan hydrogel for the encapsulation of Tβ4, which allowed its controlled release over 28days to elicit localized and prolonged effects. Contrastingly, Tβ4 was fully released over 3days when encapsulated in collagen-only hydrogels due to charge repulsion and lack of interconnected pores as shown by SEM. The charge of encapsulated molecules affected their release from collagen-chitosan hydrogels. While the release of neutral polyalanine was size-controlled diffusion, that of negatively-charged Tβ4 and positively-charged polylysine was affected by electrostatic interactions of peptides with collagen/chitosan molecules. Hydrogels with encapsulated Tβ4 significantly increased cell migration and outgrowth of CD31-positive capillaries from mouse and rat epicardial explants in vitro, compared to Tβ4-free and soluble controls. Potential advantage of Tβ4 over commonly-used angiogenic growth factors is that it can induce recruitment and differentiation of both endothelial and smooth muscle cells necessary for vascular stability. Importantly, Tβ4-encapsulated collagen-chitosan hydrogels promoted angiogenesis in vivo upon subcutaneous injection, compared to collagen-only hydrogels.

Evaluation of skeletal and cardiac muscle function after chronic administration of thymosin beta-4 in the dystrophin deficient mouse

Thymosin beta-4 (Tβ4) is a ubiquitous protein with many properties relating to cell proliferation and differentiation that promotes wound healing and modulates inflammatory mediators. We studied the effects of chronic administration of Tβ4 on the skeletal and cardiac muscle of dystrophin deficient mdx mice, the mouse model of Duchenne muscular dystrophy. Female wild type (C57BL10/ScSnJ) and mdx mice, 8–10 weeks old, were treated with 150 µg of Tβ4 twice a week for 6 months. To promote muscle pathology, mice were exercised for 30 minutes twice a week. Skeletal and cardiac muscle function were assessed via grip strength and high frequency echocardiography. Localization of Tβ4 and amount of fibrosis were quantified using immunohistochemistry and Gomori's tri-chrome staining, respectively. Mdx mice treated with Tβ4 showed a significant increase in skeletal muscle regenerating fibers compared to untreated mdx mice. Tβ4 stained exclusively in the regenerating fibers of mdx mice. Although untreated mdx mice had significantly decreased skeletal muscle strength compared to untreated wild type, there were no significant improvements in mdx mice after treatment. Systolic cardiac function, measured as percent shortening fraction, was decreased in untreated mdx mice compared to untreated wild type and there was no significant difference after treatment in mdx mice. Skeletal and cardiac muscle fibrosis were also significantly increased in untreated mdx mice compared to wild type, but there was no significant improvement in treated mdx mice. In exercised dystrophin deficient mice, chronic administration of Tβ4 increased the number of regenerating fibers in skeletal muscle and could have a potential role in treatment of skeletal muscle disease in Duchenne muscular dystrophy.

[Effectiveness and safety of bicyclol combined with thymosin in treatment of chronic viral hepatitis B]

OBJECTIVE

To analyze the efficacy and safety of bicyclol combined with thymosin in treatment of chronic viral hepatitis B (CHB).

METHODS

A total of 135 patients with CHB were randomized into experimental group and control group. The patients in the experimental group received bicyclol orally 75 mg daily and thymosin 20 mg intramuscular injection once every 2 days for 24 weeks and those in control group received bicyclol orally 75 mg daily alone for 24 weeks. The levels of serum aminotransferase (ALT/AST), HBV-DNA, HBeAg /antiHBe were observed.

RESULTS

Compared with pre-treatment levels, the serum aminotransferase levels decreased significantly in both groups, but there were no statistically significant differences between them. HBeAg negative conversion rate was significantly higher in the experimental group than in the control group (35.3 percent vs.19.4 percent, P less than 0.05). HBV DNA negative conversion rate was significantly higher in the experimental group than in the control group (36.7 percent vs. 20.9 percent, P less than 0.05). No obvious adverse events which were probably related to the drugs were observed in this study.

CONCLUSION

The combination of bicyclol with thymosin had better effect in treatment of chronic hepatitis B ias compared with bicyvlol alone.

Epidermolysis bullosa: a genetic disease of altered cell adhesion and wound healing, and the possible clinical utility of topically applied thymosin beta4

Inherited epidermolysis bullosa (EB), having an overall incidence of only about 19 in every 1 million live births, encompasses many phenotypically and genotypically distinct diseases characterized by the presence of recurrent blisters, mechanical fragility of the skin and other epithelial structures (most notably the cornea and gastrointestinal tract), and scar formation. Each disease is the result of mutations within any of 10 specific structural proteins (keratins, laminins, collagens, integrins) within the basilar keratinocyte or the skin basement membrane zone. Two of the more severe subtypes, junctional and dystrophic EB, often involve many extracutaneous tissues. If severe, these conditions may be life threatening. Recent studies in wounds that had been artificially induced on normal skin, both in rodents and in human volunteers, have suggested that thymosin beta4 may be effective in promoting epithelial migration across the wounds. A randomized double-blind clinical trial has been recently organized to determine whether this novel biologic agent may be beneficial in promoting wound healing in patients with junctional and dystrophic EB. To do so, a solitary noninfected cutaneous wound of standardized size will be treated topically on a daily basis with either one of three concentrations of thymosin beta4 or a placebo control. Serial wound healing will be quantitated by computerized digital-imaging technique. At the same time, the occurrence of adverse effects will be sought, so as to confirm the safety of thymosin beta4 when applied to EB skin, both in children and in adults. Although as yet unproven, topically applied thymosin beta4 may prove to be an extremely important addition to the overall management of patients with this potentially devastating disease.

Immunoregulation of thymosin alpha 1 treatment of cytomegalovirus infection accompanied with acute respiratory distress syndrome after renal transplantation

We are the first to report the use of thymosin alpha1 to treat cytomegalovirus infection accompanied with acute respiratory distress syndrome after renal transplantation. The patients were divided into the thymosin alpha1 group (Zadaxin group, n = 32) and the control group (n = 14). All patients received the same rescue therapy protocol. Suitable antiviral (ganciclovir, 5 mg/kg every 12 hours, intravenously), antibacterial, or antifungal treatment was given if needed. In addition, patients in the Zadaxin group received thymosin alpha1, (1.6 mg) subcutaneously every other day or every day. The rescue success rate was significantly higher in the Zadaxin than in the control group (78.1% vs 50.0%) while the death rate was greatly reduced (21.9% vs 50%). In the Zadaxin group, the CD4(+) lymphocyte level was significantly increased on day 14; so was the ratio of CD4(+) and CD8(+) T-lymphocyte subsets. In the survival group, CD4(+) and CD8(+) lymphocyte cell counts were significantly increased on days 7, 14, and 21 compared with admission. This study suggested that thymosin alpha1 significantly promoted CD4(+) and CD8(+) lymphocytes, repairing cellular immunity and successfully reinforcing resistance to cytomegalovirus disease.

[Preparation and properties of Talpha1 loaded injectable sustained release microspheres]

To prepare thymosin alpha-1 (Talpha) loaded injectable sustained release microspheres and to evaluate its release behavior, bioactivities in vitro as well as its pharmacodynamics in vivo, Talpha1 loaded microspheres was prepared with poly ( lactic-co-glycolic acid) (PLGA) as carrier material by double emulsion (W/O/W) method. Physical and chemical properties of microspheres, such as mean diameter, The release behavior and its influencing factors were morphology and drug loading were evaluated. evaluated by HPLC determination. The bioactivity of Talpha1 in the course of encapsulation process and in vitro release ware evaluated by CCK-8 method. The ratio of CD4+/CD8+ in blood was determined with flow cytometry and the pharmacodynamics of Ta, loaded microspheres was evaluated by the change of CD4+/ CD8+. Microspheres with good shape and dispersive quality were prepared. The drug entrapment efficiency of two optimizing prescriptions containing 5% NaCl and 10% glucose as outer water phase were 87. 8% and 90. 2% , respectively. The cumulated release in one month is up to 90%. The bioactivity of Talpha was conserved with glucose as outer water phase, but in the course of in vitro release, the specific activity of Talpha in the microspheres decreased a little. Talpha microspheres can increase significantly the immunity of immuno-suppressed rats. Talpha can be encapsulated in injectable microspheres to yield one-month continuous release when using biodegradable polymers PLGA as carrier material, and this technique will have a favorable perspective in the near future.

Liposomal plasmid DNA encoding human thymosin alpha and interferon omega potently inhibits liver tumor growth in ICR mice

AIM

To evaluate the potential therapeutic effect of liposomal gene delivery, genes encoding for human thymosin alpha1 (Talpha1) and interferon omega1 were injected via the tail vein into mice bearing a Hep-A-22 liver tumor.

METHODS

The cDNA of human Talpha1 and interferon omega1 were obtained by synthesis or reverse transcription-polymerase chain reaction (RT-PCR), respectively. Eukaryotic expressing vectors pIRES2, encoding Talpha1 and/or interferon omega1, were constructed and injected with liposome via the tail vein into ICR mice bearing a Hep-A-22 tumor. The potency of tumor inhibition was evaluated when three treated groups were compared with the group receiving the empty vector. Apoptosis of tumor cells was investigated by analyzing DNA fragmentation.

RESULTS

Only the group treated with dual-gene plasmid reached an eligible level of tumor inhibition (43%). The difference in tumor weight was statistically significant between the Talpha1 gene or the interferon omega1 gene treated groups and the control (P<0.05), and highly significant between the dual-gene treated group and the control (P<0.01). DNA ladder was observed in the tumor cells from the purpose gene treated groups but not from the control.

CONCLUSION

The dual-gene plasmid-liposome complex showed more potent inhibition than the single gene constructs on the growth of Hep-A-22 tumor cells in mice, which may be attributed to indirect and additive induction of apoptosis in tumor cells by increased expression of Talpha1 and interferon omega1.

The current status of antiviral therapy of chronic hepatitis B

In recent years, marked progress has been made in the treatment of chronic viral hepatitis. Recent studies suggest that pegylated interferons (PEG IFNs) are more effective than standard IFNs in the treatment of chronic hepatitis B. So far, the combination of PEG IFN with lamivudine, used simultaneously, is disappointing in terms of short-term efficacy. However, long-term efficacy needs to be addressed and different schedules of combination, for example sequential, need to be evaluated. A number of nucleoside analogues, with favourable toxicity profiles and a promise of increased effectiveness against HBV, are in various stages of clinical development. Entecavir has recently been approved in the USA. The future of chronic hepatitis B therapy seems to be in the combination of different drugs. Ideally, the optimal drugs to combine would meet the following criteria: they should have a potent antiviral effect, an excellent safety profile and the duration of therapy should be limited. Indeed, the concept of combination therapy has been recently developed in order to increase efficacy and to decrease the occurrence of viral resistance. However, so far there are few data available and no combination therapy demonstrated a clear benefit as compared with monotherapy. More potent drugs and new combinations together with the understanding of the mechanisms of resistance to therapy are challenges to improve the efficacy of treatment and decrease in the future the global burden related to chronic hepatitis B.

Antiviral therapy using lamivudine and thymosin alpha1 for hepatocellular carcinoma coexisting with chronic hepatitis B infection

BACKGROUND/AIMS

To observe the recurrence and prognosis of patients with hepatocellular carcinoma (HCC) coexisting with chronic hepatitis B infection with active virus replication after receiving antivirus therapy using lamivudine and thymosin alpha1 postoperatively.

METHODOLOGY

From Jan. 2000 to Dec. 2002, 33 patients with HCC coexisting chronic hepatitis B infection with active virus replication were prospectively divided into two groups: control group (n= 17) received hepatectomy only, treatment group (n= 16) received hepatectomy and lamivudine plus thymosin alpha1 therapy postoperatively. The suppression of HBV-DNA, HBeAg seroconverted rate, recurrent tumor rate and the median survival for the two groups were observed and calculated.

RESULTS

For the treatment group and control group, the one-year HBV-DNA suppression rate was 100% vs. 6% (p=0.0016); HBeAg seroconverted rate was 62.5% vs. 5.9% (p=0.0157); The median recurrent time was 7.0 vs. 5.0 months (p=0.0052); The median survival period was 10.0 vs. 7.0 months (p=0.10053), respectively.

CONCLUSIONS

Antivirus therapy using lamivudine and thymosin alpha1 postoperatively may suppress the HBV reaction, delay the recurrent time and prolong the survival for HCC patients coexisting with chronic HBV infection with active virus replication.

Immunomodulatory function of orally administered thymosin alpha1

OBJECTIVE

To investigate the immunological function of a yeast expression system for thymosin alpha1 (Talpha1).

METHODS

A constructed Talpha1 yeast expression system was used to investigate the immunological function of orally administered Talpha1. Dried yeast containing three different concentration of Talpha1 was fed to normal Balb/c mice and other Balb/c mice whose immunities were inhibited in advance by cyclophosphamide. Synthesized Talpha1 peptide was used as positive control and dried yeast with empty plasmid was used as negative control. CD4(+) and CD8(+) levels were detected by flow cytometry assay. TNF-alpha, IFN-gamma, IL-2, IL-6 and IL-10 levels were detected by liquid chip.

RESULTS

In normal Balb/c mice or immune inhibition Balb/c mice, CD8(+) levels were significantly increased. Especially in immune inhibition Balb/c mice, CD8(+) levels in synthesized Talpha1 group (18.77%+/-4.72%), small dose group (13.48%+/-6.17%) and large dose group (22.74%+/-1.09%) were significantly higher than that in empty yeast control group (7.49%+/-2.14%).

CONCLUSION

Orally administered Talpha1 has its certain immunomodulatory function.

Thymosin-loaded enteric microspheres for oral administration: Preparation and in vitro release studies

Thymosin, a water-soluble polypeptide compound, was encapsulated within enteric microspheres of acrylic acid resin II by modified oil in oil (o/o) emulsion solvent evaporation method. The mixture emulsifier composed of lecithin and Span 80 was critical to the formation of sphere-shaped thymosin microparticles. Optimizing process parameters, such as the volume ratio of organic solvent to water, initial drug feed and polymer concentration, resulted in high drug encapsulation efficiency of 89.7% (6% polymer concentration and 0.5% initial drug feed). In vitro release studies suggested that thymosin release from microspheres exhibited pH dependent profiles. For formulation with 6% polymer concentration and 0.5% initial drug feed, 68.7% thymosin was released within 4h in pH 6.8 PBS buffer, while only 6.5% was observed in acid medium.

Enhancement of humoral and cellular immune responses by an oral Salmonella choleraesuis vaccine expressing porcine prothymosin alpha

Previously, we showed that murine prothymosin alpha (ProT) enhances the efficacy of a pseudorabies DNA vaccine delivered by bacterial vectors. In this study, we cloned and sequenced the cDNA for porcine ProT. The deduced amino acid sequence of porcine ProT exhibited high homology to ProT from other mammals. Oral Salmonella choleraesuis vaccine carrying the ProT eukaryotic expression plasmid protected mice against virulent S. choleraesuis challenge. The adjuvant effect of ProT on humoral and cellular immune responses enhanced protective efficacy of the vaccine. Furthermore, both humoral and cellular immune responses played roles in the protective immune responses induced by the vaccine. Collectively, our results show that delivery of the ProT gene carried by attenuated S. choleraesuis augmented the immunogenicity of oral S. choleraesuis vaccine.

The efficacy and safety of thymosin alpha-1 in Japanese patients with chronic hepatitis B; results from a randomized clinical trial

Thymalfasin (thymosin alpha-1; Talpha1) is a 28-amino acid polypeptide that has shown efficacy in the treatment of chronic hepatitis B virus (HBV) infection. The objective of this study was to evaluate the long-term, dose-related efficacy and safety of Talpha1 treatment in chronic hepatitis B patients with positive HBV-DNA and abnormally high alanine aminotransferase (ALT) levels. A total of 316 patients were randomized to receive either 0.8 or 1.6 mg of Talpha1 monotherapy for 24 weeks. At the end of the 72-week observation period (12 months after cessation of therapy), 36.4% of patients in the 1.6-mg treatment group achieved normalization of ALT, 30% achieved clearance of HBV-DNA by branched DNA vs 15% by transcription-mediated amplification, and 22.8% achieved clearance of HBe-antigen. Patients in the 0.8-mg treatment group achieved similar efficacy rates, although patients with advanced fibrosis demonstrated a significantly better response rate when treated with 1.6 mg of Talpha1 monotherapy vs 0.8 mg (as determined by intragroup analysis; patients were not stratified by liver biopsy). All adverse drug reactions were mild and most involved the fluctuation of liver enzymes, which was most likely related to the positive immune effects caused by the response to Talpha1 treatment. Adverse event incidence was similar in the 1.6- and 0.8-mg treatment groups. In conclusion, Talpha1 at doses of 0.8 and 1.6 mg exhibits long-term efficacy against hepatitis B with a good safety profile.

[Effects of cytokines on the immunogenic properties of hepatitis A vaccine]

Cytokines were found, in experiments with guinea pigs, to have a stimulating action on the immunogenic potency of hepatitis A vaccine (Hep-A-in-Vac). The most pronounced effects were produced by rhIL-1b, rhTNF-alpha, thymosin-a1, the "neothym" hybrid protein and immunophan. Injections of cytokines as of adjuvants stimulated the formation of antibodies titers that exceeded 2-10-fold those observed in control animals immunized by Hep-A-in-Vac alone. Immunization of guinea pigs made alongside with injections of the above cytokines ensured a 100% seroconversion in animals after the administration of drugs was completed. The number of seropositive animals in the control group was 75-89%.

Combination therapy of thymalfasin (thymosin-alpha 1) and peginterferon alfa-2a in patients with chronic hepatitis C virus infection who are non-responders to standard treatment

The worldwide spread of hepatitis C virus is enormous; chronic hepatitis C virus infection is a leading cause of liver cirrhosis and hepatocellular carcinoma. While treatment options have improved substantially over the last decade, responses are still disappointing, particularly in certain difficult-to-treat groups such as patients who are immunosuppressed or have decompensated disease. Preliminary studies have indicated that combined treatment strategies may provide effective approaches for the future. The combination of thymalfasin with pegylated interferon is currently a promising option for the treatment of patients with chronic hepatitis C virus infection. An ongoing phase 3 study in the USA should provide much needed data to improve the outcome for these patients.

Combination therapy of thymalfasin (thymosin-alpha 1) and peginterferon alfa-2a in patients with chronic hepatitis C virus infection who are non-responders to standard treatment

The worldwide spread of hepatitis C virus is enormous; chronic hepatitis C virus infection is a leading cause of liver cirrhosis and hepatocellular carcinoma. While treatment options have improved substantially over the last decade, responses are still disappointing, particularly in certain difficult-to-treat groups such as patients who are immunosuppressed or have decompensated disease. Preliminary studies have indicated that combined treatment strategies may provide effective approaches for the future. The combination of thymalfasin with pegylated interferon is currently a promising option for the treatment of patients with chronic hepatitis C virus infection. An ongoing phase 3 study in the USA should provide much needed data to improve the outcome for these patients.

Triple combination of thymalfasin, peginterferon alfa-2a and ribavirin in patients with chronic hepatitis C who have failed prior interferon and ribavirin treatment: 24-week interim results of a pilot study

Despite steady progress in antiviral treatment for patients with chronic hepatitis C virus(HCV), many patients still have detectable serum HCV RNA levels by the end of interferon-based treatment and are known as virological non-responders. Re-treatment of these patients not responding to previous therapy remains challenging. Studies of the dynamics of the HCV population show a marked decline in new cases since 1996; however, the relative proportion of non-responders is expected to increase over time and, similarly, the number of patients eligible for first-line treatment is expected to decrease. The current standard of care for treatment involves the use of pegylated interferons in combination with ribavirin. However, many difficult-to-treat groups still have low response rates. Newer combinations are being investigated to optimize chances of attaining a sustained response in these groups: one such triple therapy regimen is peginterferon alfa-2a, ribavirin and thymalfasin, which was given to 23 previously non-responder patients. Viral response was 60.8% at week 12 and 47.8% at week 24. These preliminary results encourage further evaluation of this promising combination.

Retreatment of patients who do not respond to initial therapy for chronic hepatitis C

Despite improvements in the treatment of chronic hepatitis C virus (HCV) infection, nearly half of all patients do not respond to initial therapy. Retreatment of these patients with pegylated interferon and ribavirin has been successful in only a limited percentage of cases. Factors associated with sustained virologic response (SVR) following retreatment include prior treatment with interferon monotherapy, HCV genotype 2 or 3, a low serum HCV RNA level, and the absence of cirrhosis. Fewer than 6% of nonresponders who were previously treated with interferon and ribavirin and who have cirrhosis, genotype 1, and a high viral load achieve SVR following retreatment with pegylated interferon and ribavirin. No therapy has been shown to yield SVR in patients who do not respond to pegylated interferon and ribavirin. Long-term maintenance therapy with pegylated interferon is currently being evaluated in nonresponders with advanced fibrosis and cirrhosis. Its use should be considered investigational at this time.

Activation of tumor-associated macrophages by thymosin alpha 1

It was shown earlier that the progressive growth of a transplantable T-cell lymphoma of spontaneous origin, designated as Dalton's lymphoma (DL), in a murine host is associated with an inhibition of macrophages (TAM) along with an involution of thymus. However, it remained unclear if a decline in the level of thymic peptides in DL-bearing host, due to thymic regression, has any implications in the inhibited responses of TAM. Therefore, the present investigation was under taken to study whether the TAM of DL-bearing host can be activated to tumoricidal state by peptides of thymic origin. It was observed that intraperitoneal administration of thymosin alpha 1 to DL-bearing mice resulted in activation of TAM. Such TAM were found to produce enhanced amount of interleukin-1 (IL-1), tumor necrosis factor (TNF), reactive oxygen intermediates (ROI), nitric oxide (NO) and showed an increased abilities of pinocytosis, phagocytosis, antigen presentation and tumor cytotoxicity. The TAM were found to be directly responsive to thymosin alpha1 as in vitro treatment with thymosin alpha 1 could activate TAM to tumoricidal state. Treatment of TAM with thymosin alpha 1 also enhanced their LPS responsiveness for an augmented state of activation. The findings of this study demonstrate for the first time that the TAM of a T cell lymphoma can be activated to tumoricidal state by thymosin alpha 1.

[Transcatheter hepatic arterial chemoembolization and thymosin alpha1 in postoperative treatment of hepatocellular carcinoma]

OBJECTIVE

To observe the effect of postoperative transcatheter hepatic arterial chemoembolization (TACE) and thymosin alpha(1) (T(alpha1)) treatment on recurrence of hepatocellular carcinoma (HCC).

METHODS

From Jan 2000 to Dec 2002, 57 patients with HCC were randomly divided into three groups: group A (n = 18) received hepatectomy plus postoperative TACE and T(alpha1), group B (n = 23) received hepatectomy plus postoperative TACE and group C (n = 16) received hepatectomy only. The recurrence rate, the time to tumor recurrence and the median survival for the three groups were investigated.

RESULTS

For group A, B and C, the 1 year recurrence rate was 83.3%, 87.0% and 87.5% (P = 0.926), respectively. The time to tumor recurrence was 7.0, 5.0 and 4.0 months (P = 0.039), respectively. The median survival was 10.0, 7.0 and 8.0 months (P = 0.002), respectively.

CONCLUSION

Postoperative TACE plus Talpha(1) treatment for HCC patients does not decrease the recurrence rate but may delay its occurrence and prolong surviving time.

[Clinical trial of sequential antiviral therapy for patients with chronic hepatitis B in China]

OBJECTIVE

To establish a sequential antiviral regime and evaluate its efficacy in patients with chronic hepatitis B using a controlled trial.

METHODS

Seventy-four patients with chronic hepatitis B were divided into 3 groups: 30 cases were enrolled in the sequential antiviral group in which patients received eight-week treatment with thymosin alpha1 (1.6 mg/time, subcutaneous injection, 2 times/week), six-month treatment with interferon (500 MU/ times, muscle inject, every other day) begun in the fifth week of the therapeutic course, and lamivudine treatment (100 mg/days) begun 2 months later after HBeAg seroconversion or just after the withdrawal of interferon to more than eighteen months. Fourteen cases were enrolled in combination group in which patients received six-month treatment with interferon and thymosin alpha1 simultaneously in the same manner as in sequential antiviral group. Thirty cases were enrolled in lamivudine group in which patients received more than eighteen-month treatment with lamivudine.

RESULTS

The temporary rates of HBeAg seroconversion and normalization of alanine aminotransferase (effective rate) in sequential antiviral group, combination group and lamivudine group were 76.7%, 78.6% and 13.3%, respectively. The effective rates of sequential group and combination group were very similar, and significantly higher than that of lamivudine group (P less than 0.01). Long-term efficacy rates were 76.7%, 57.1% and 16.7% among the three groups, respectively. The long-term effective rate of sequential group was relatively higher. The rate of liver damage sensitive period in sequential antiviral group and combination group was 47.7%. The time of onset was from 2 to 8 weeks after the treatment begun, earlier than that from 6 to 8 weeks after the beginning of interferon alone in the literature.

CONCLUSION

Sequential antiviral therapy had much higher rates of long-term HBeAg seroconversion, undetectable HBV DNA and normalization of alanine aminotransferase with good cost-effectiveness. Its mechanism to promote the antiviral effect might be dependent on the immunoregulatory action of thymosin alpha1 in the earlier period and the specific inhibition of HBV DNA replication by lamivudine in the later period of the therapeutic course.

Thymosin-alpha 1 plus interferon-alpha for naive patients with chronic hepatitis C: results of a randomized controlled pilot trial

In this pilot study, we evaluated the efficacy of interferon-alpha (IFN) plus Thymosin-alpha 1 (TA1) to that of IFN alone in naive patients with chronic hepatitis C. Twenty-two patients were randomized to receive interferon-alpha 2b (3 million units three times a week) plus thymosin-alpha l (900 microg/m2 body surface area) and 19 received interferon-alpha 2b alone at the same dose. Patients were treated for 6 months and followed up for another 6 months. Biochemical (alanine aminotransferase values) and virological (hepatitis C virus-RNA) responses to treatment were determined. Combination treatment showed significantly higher efficacy than monotherapy in achieving virological end-of-treatment response (P = 0.03). At 6-month follow up, the sustained biochemical and virological response was not different between the two groups. Our results indicate that the immune modulator TA1 may enhance the end-of-treatment response in naive patients with chronic hepatitis C. Higher doses and/ore more prolonged courses as well as the association with new interferon formulation such as pegylated interferons could improve the sustained response rates to this treatment.

Thymosin alpha(1) in combination with cytokines and chemotherapy for the treatment of cancer

Multiple therapeutic approaches have been tested in different experimental tumour models and in human cancers. Most part of them are based on the hypothesis that the inhibition of tumour growth requires a strong immune response in which a main role is played by CTLs. It is known, however, that an efficient CTL response requires expression of tumour antigens, MHC class I surface molecules presentation, expression of different co-stimulatory molecules and a sustained generation and proliferation of specific cytotoxic CD8+ cells with an efficient CD4+ cooperation. In this context, our group has extensively explored a protocol of combined therapy consisting of the use of chemotherapeutic agents associated with thymosin alpha 1 (Talpha 1) and different cytokines, whose efficacy has been demonstrated in experimental models as well as in human cancers. In this manuscript, the main data supporting a pivotal role of Talpha 1 in such combination protocols are reviewed. In particular, a special mention of the molecular mechanisms underlying the effects of Talpha 1 on immune effector cells as well as on target tumour cells is provided. These data contribute to explain the mechanism of action of Talpha 1, when used in combination therapy, for the treatment of cancer and provide new insights in predicting further possible applications of this peptide in other pathological conditions.

Thymosin beta(4) reduces lethality and down-regulates inflammatory mediators in endotoxin-induced septic shock

Thymosin beta(4) (Tbeta(4)), a highly conserved peptide with immunomodulatory properties, is the major actin-sequestering peptide in mammalian cells. Recent studies have established that Tbeta(4) can accelerate wound healing in full thickness skin wounds and following burn injuries to the cornea. In the eye studies, the accelerated healing due to Tbeta(4) was accompanied by a significant reduction in polymorphonuclear leukocyte (PMN) infiltration and a several-fold decrease in interleukin-1beta (p< or =0.015) and 6-keto-prostaglandin F(1alpha) (6-keto-PGF1alpha, p< or =0.05). Given the recognized role of proinflammatory cytokines in septic shock and of extracellular F- and G-actin in the pathophysiology of multiple organ dysfunction, we have investigated the role of Tbeta(4) in sepsis. We report that an LD(50) dose of LPS (24 mg/kg) in rats resulted in a significant reduction of Tbeta(4) levels in the blood. Furthermore, administration of 100 microg of Tbeta(4) immediately following and at 2 and 4 h after an LD(50) dose of LPS (60 mg/kg) in mice significantly reduced mortality rates (p< or =0.024) and lowered blood levels of a number of inflammatory cytokines, eicosanoids, and other molecules that are highly elevated following endotoxin administration. In studies in human subjects given low doses of endotoxin (4 ng/kg LPS) and in patients with septic shock, we have also observed significant decreases in blood levels of Tbeta(4). The rapid disappearance of Tbeta(4) in the blood following LPS administration or during septic shock suggests that Tbeta(4) may be involved in early events leading to activation of the inflammatory cascade and ultimately the clinical sequelae of sepsis. The results of this study indicate that Tbeta(4) may have utility in the clinic in the treatment of septic shock and in syndromes associated with actin toxicities.

Thymosin beta4 promotes human conjunctival epithelial cell migration

PURPOSE

In this study the effects of thymosin beta4 (Tbeta4) on migration and production of laminin-5 in the human conjunctival cell line HC0597 was analyzed.

METHODS

Boyden chamber assays assessed the ability of Tbeta4 to stimulate in vitro cell migration. Control or Tbeta4-treated cells were processed for immunofluorescence microscopy using antibodies to vinculin or laminin-5. Cell lysates were processed for Western blot and densitometric analysis using antibodies to laminin-5 alpha3 or gamma2 chains.

RESULTS

Tbeta4 stimulated migration in a dose-dependent manner. Focal adhesions present in Tbeta4-treated cells were smaller and more rounded compared to the "streaks" characteristic of controls. Western blot analysis and densitometry revealed that Tbeta4-treated cells expressed more laminin-5 alpha3 and gamma2 chain protein.

CONCLUSION

Tbeta4 stimulates in vitro conjunctival epithelial cell migration, and results in altered focal adhesion formation and increased extracellular laminin-5 deposition. The increased migration may be correlated with increased production of laminin-5.

Treatment of chronic hepatitis B: case selection and duration of therapy

Hepatitis B viral (HBV) infection is a major health burden in the Asia-Pacific region. The seriousness of chronic hepatitis B (CHB) is often realized at a late stage. The resultant morbidity and mortality from cirrhosis complications is considerable, with a high human cost. The most affected patients are men aged 40 years or older. Two decades ago, the prognosis for the 300 million "Australia antigen"-positive people (people with chronic HBV infection) was gloomy, with no effective intervention. Twenty years on, research and development have changed their outlook. Chronic hepatitis should now be diagnosed early, at the asymptomatic stage. Proper assessment and judicial introduction of therapy can suppress replication of HBV and resolve liver inflammation, thereby preventing the silent progression of chronic liver disease to end-stage cirrhosis. Interferon (IFN) monotherapy has been available for nearly 20 years, but various limitations restrict its general application. Injection-based therapies are inconvenient, the response rate is low (33% hepatitis B e antigen (HBeAg) seroconversion rate among optimal cases), side-effects are many, and some serious, and the cost is unaffordable for most people. However, in non-cirrhotic patients with mild to moderate disease activity, IFN is still a worthwhile option because the treatment course is shorter, mutation seems less of a problem and most responses are permanent and reduce or abolish late complications. Lamivudine, an oral nucleoside analog with potent antiviral effects, has been approved in many countries. Daily dosing of 100 mg reduces serum HBV-DNA to below detectable levels within 6 weeks. In HBeAg-positive patients, approximately 16% of treated patients seroconverted with the first year. This was associated with significant improvement in liver histology. Long-term treatment induces further HBeAg seroconversion, but overall clinical benefit is undermined by continuous emergence of drug-resistant YMDD mutants. In an Asian multicentre study, 58 patients on 5 years lamivudine therapy showed annual cumulative HBeAg seroconversion rates at 1, 2, 3, 4 and 5 years of 22, 29, 40, 47 and 50%, respectively. The best predictor of response is pretreatment alanine aminotransferase (ALT). Among patients with ALT > 2x the upper limit of normal (ULN), annual HBeAg seroconversion is increased to 38, 42, 65, 73 and 77%, respectively. However, emergence of YMDD mutants occurred at a cumulative rate of 15, 38, 55, 67 and 69%, respectively. The impact of this emergence on disease activity is unpredictable. Thus, while continued disease suppression, or even HBeAg seroconversion, still occurred in some patients, in others hepatitis may relapse and liver failure has been reported despite continuation of lamivudine. While the duration of lamivudine therapy is difficult to define, the best strategy may be to define only active CHB with major ALT elevation (par-ticularly ALT > 5x ULN) for a duration of 1 year or less. Lamivudine can be stopped in responders. The response is durable in approximately 80% of responders. Non-responders should be monitored closely for rebound off treatment. Therapy can be re-instituted if ALT is over 5x ULN. Management of patients with YMDD mutants can be challenging, but there is no clear evidence to recommend stopping or continuing lamivudine, or to add other possible effective agents, such as adefovir dipivoxil. More data are required to help draw up guidelines. Hepatitis B e antigen-negative CHB has been less well studied. Both IFN and lamivudine can suppress disease activity, but permanent responses are few. Without a distinct marker as an end-point for response, the duration of treatment is even more difficult to define. Quantitative polymerase chain reaction for low viral levels may give a clue, but definitive studies are required. Monotherapy is clearly not the answer for the majority of CHB patients with active disease. Combination therapy has the theoretical advantage of additional or synergistic efficacy. Preliminary results on IFN and lamivudine are promising and further clinical trials are ongoing. Emtricitabine (FTC), adefovir dipivoxil, entecavir, BL-thymidine (L-dT), DAPD, clevudine (l-FMAU), thymosin, therapeutic vaccines and various herbal medicines are potential candidates. Antiviral action in conjunction with immune modulation may have a better chance of eradicating HBV and its cccDNA in the hepatocytes as the basis for an eventual successful outcome. The key points are: (i) approved therapeutic agents for chronic hepatitis B (CHB) are IFN, lamivudine and thymosin (in a few countries only); (ii) indications for IFN therapy are viremia in compensated CHB patients with moderately raised ALT; (iii) lamivudine has broader therapeutic indications: it is effective in subgroups of CHB patients with compensated or decompensated liver diseases, but generally works better if patients have raised ALT; (iv) lamivudine has a potent suppressive action on HBV replication, including HBeAg-negative variants, but cannot eliminate cccDNA; this is the reason for the relapse of disease after discontinuing treatment, unless HBeAg seroconversion is obtained; (v) successful use of lamivudine aims at HBeAg seroconversion or profound suppression of HBV-DNA to serum levels of less than 100 000 viral copies/mL, in order to prevent emergence of drug-resistant YMDD mutants (which commences from 6 months onward); (vi) YMDD mutants may cause a flare of hepatitis, resulting in deterioration of liver histology and, occasionally, liver failure; (vii) combination therapy of lamivudine with IFN (standard or pegylated) or other nucleoside analogs should be the next advance. Preliminary data from IFN and lamivudine combination therapy show some promise, but there are conflicting results.

Prothymosin alpha enhances protective immune responses induced by oral DNA vaccination against pseudorabies delivered by Salmonella choleraesuis

Previously, we showed that vaccination with the glycoprotein D (gD) gene of pseudorabies virus (PrV) delivered by Escherichia coli induced protective immune responses. In this study, we report that oral DNA vaccination with attenuated Salmonella choleraesuis carrying the PrV gD gene conferred protective immunity in mice against PrV. Moreover, co-delivery of the prothymosin alpha gene carried by S. choleraesuis enhanced the vaccine efficacy. Our results thus demonstrate for the first time, to our knowledge, the effectiveness of oral DNA vaccination using S. choleraesuis as a delivery vehicle and the potential usefulness of prothymosin alpha as a DNA vaccine adjuvant.

The combined treatment of interferon alpha-2a and thymosin alpha 1 for chronic hepatitis C: the 48 weeks end of treatment results

The efficacy and safety of IFN alpha 2a and Thymosin alpha1 combination therapy in patients with chronic hepatitis C were determined. Twelve chronic hepatitis C patients (9 M, 3F), with positive HCV-RNA and histology compatible with chronic hepatitis C were included in this open, prospective study. Each patient received a combination therapy of IFN alpha 2a 3 mU s.c. TIW and Thymosin alpha1 1.6 mg s.c. twice a week for 52 weeks. Up to the present, 11 patients are still being followed-up after the end of 52 weeks' treatment. One patient dropped out after 32 weeks of follow-up due to noncompliance. Responses to treatment were evaluated by measuring serum HCV-RNA levels determined by RT-PCR. and serum amino transferases at the end of 48 weeks of treatment (end of treatment response: ETR). There were 8 naive and 4 previously IFN treated patients with partial response with a mean age of 45.0 +/- 10.1 (mean +/- SD). The mean duration from diagnosis until treatment was 25.1 +/- 22.9 months. The mean AST, ALT, and HCV-RNA levels before treatment were 79.5 +/- 36.8 U/L, 128.3 +/- 68.5 U/L, and 3.9+1.9 x 10(5) copies/ml respectively. Serum AST, ALT, and HCV-RNA levels were significantly lower at week 24 and 48 after treatment compared to before treatment (p<0.05). Of 11 cases, complete HCV-RNA clearance at week 24 was noted in 33.3 per cent, whereas, normal alanine aminotransferase values (ALT < 40 U/L) were observed in 41.7 per cent of patients. Complete HCV-RNA clearance and normal alanine aminotransferase at week 48 were seen in 45.5 per cent of the patients. At the end of week 48, complete response occurred in 4 of 5 naive patients. Minor side effects were observed during treatment with this combination therapy and these included myalgia (33.3%), mild form of alopecia (33.3%), and weight loss (8.3%). In patients with chronic hepatitis C, Interferon alpha 2a and Thymosin alpha1 combination therapy produced a good response rate especially in naive patients with acceptable safety profile. The sustained response will be determined after the completion of follow-up for another 6 months.

[The effect of IFN-alpha 2b-thymus peptides combined therapy in chronic hepatitis B]

OBJECTIVE

To determine the effects of IFN-alpha 2b associated with thymus peptides in treatment of chronic hepatitis B.

METHODS

A total of 52 individuals with chronic hepatitis B received IFN-alpha 2b(5 x 10(6) IU/ml qod) for 6 months and thymus peptides(20 mg qod) for 3 months. 50 patients received SMMC or other medicine such as WuWeizi, CuiPenCao served as control. There were no differences between two groups in sex, age, duration and seriousness of the disease.

RESULTS

The primary outcome measure for efficacy was the percentage of HBV DNA/HBeAg negativity after 6 months therapy. Rate of HBV DNA negativity was 75% and that of HBeAg was 73.1%, the inhibitory activity of IFN-alpha 2b against HBV was significantly higher than that of the control. Except transient fever, leukopenia and thrombocytopenia appearing at the beginning of the therapy, no serious adverse events were observed.

CONCLUSION

Potent inhibitory activity against HBV of IFN-alpha 2b is suggested and much works need to be done to improve the long-term effect of the therapy.

Restoration of immunocyte functions by thymosin alpha1 in cyclophosphamide-induced immunodeficient mice

Thymosin alpha1 (Talpha1) is an oligopeptide hormone originally isolated from the thymus gland, and has been reported to have stimulating effects on the differentiation of T cells and NK cells. These immunostimulating properties have been considered to be useful for improving immune disorders associated with various diseases including cancer, AIDS and hepatitis. Here, we characterized immunostimulating properties of Talpha1 in experimental immunodeficiency of mice that was induced by the administration of cyclophosphamide (CY). Repeated injection of 30-300 microg/kg/day of Talpha1 after CY-treatment significantly accelerated the restoration of the reduced number of CD4+CD8+ T cells in the thymus. Talpha1 administration was effective in restoring the suppressed activities of helper T cells and cytotoxic T cells in CY-treated mice. Talpha1 also had stimulating effects on reduced activity of lymphokine-activated killer cells in CY-treated mice. These results indicate that Talpha1 is stimulatory for both humoral and cellular immune responses, thus providing the immunological basis for the clinical benefit of this compound.

Augmentation of antitumor activity of 5'-deoxy-5-fluorouridine by thymosin fraction 5 in mouse bladder cancer cells in vitro and in vivo

5'-Deoxy-5-fluorouridine (5'-dFUrd) is a prodrug of 5-fluorouracil (5-FUra) activated by pyrimidine nucleoside phosphorylase (PyN Pase), mainly by uridine phosphorylase (Urd Pase) in rodents and by thymidine phosphorylase (TdR Pase) in humans, which is preferentially located in tumor tissues compared to normal tissues. It has been reported that PyN Pase is induced by cytokines such as tumor necrosis factor (TNF), interleukin-1alpha (IL-1alpha) and interferon (IFN). Thymosin is a glycoprotein extract obtained from the calf thymus and is a potent immunopotentiating preparation. In this study, the antiproliferative activity of 5'-dFUrd used in combination with thymosin fraction 5 (TF5) was investigated in mouse bladder cancer cell line MBT-2 in vitro and in vivo. In vitro TF5 enhanced the activity of 5'-dFUrd by up to 4.11-fold, whereas the activity of other cytostatics such as 5-FUra, mitomycin C, adriamycin, cis-platinum, etoposide, vinblastine and methotrexate was not changed. In vivo when the effects of combination therapy with 5'-dFUrd and TF5 in C3H/HeN mice implanted with MBT2 were studied, tumor growth was not suppressed by TF5 alone while tumor growth was suppressed to some degree by 5'-dFUrd alone. However, tumor growth suppression was enhanced when 5'-dFUrd was used in combination with TF5. In order to investigate this mechanism, Urd Pase in MB2 was measured, and it was found that TF5 increased enzyme activity by up to 1.8-fold in MBT2. This increased susceptibility might be a result of the induction of Urd Pase, which is the essential enzyme for the conversion of 5'-dFUrd to 5-FUra. These results suggested that the therapeutic benefit of 5'-dFUrd would be improved by its use in combination with TF5 and the modulation of converting enzymes for antitumor prodrugs could be a novel therapeutic strategy for treating human cancers.

Efficacy of repeated cycles of chemo-immunotherapy with thymosin alpha1 and interleukin-2 after intraperitoneal 5-fluorouracil delivery

We have used chemo-immunotherapy with 5-fluorouracil (5-FU), thymosin alpha1 (T alpha1) and interleukin-2 (IL-2) to treat multiple liver metastases from colorectal cancer induced by DHD/K12 cells in syngeneic BDIX rats, comparing one and two cycles of treatment, and different treatment combinations. 5-FU was delivered loco-regionally as a continuous infusion via an intraperitoneal (i.p.) catheter from a subcutaneously implanted mini-pump, a method we developed for this study. We show here that two cycles of a triple chemo-immunotherapy regimen significantly increased the average survival time compared to one cycle, and compared to untreated controls or those treated with two cycles of 5-FU alone. At 150 days, two rats treated with two cycles of triple therapy were cured, showing no signs of cancer at autopsy; all the other rats died before this time. Triple chemo-immunotherapy resulted in significantly fewer extra-hepatic metastases than in the controls and in those treated with 5-FU only. Further, we found that two cycles of triple treatment significantly increased the absolute number of peripheral T cells expressing IL-2 receptor, CD4 and CD8 compared to controls. We conclude that two cycles of chemo-immunotherapy with 5-FU, T alpha1 and IL-2 were superior to one cycle of treatment and to other treatments tested. Our results suggest that the triple therapy acts by increasing numbers of effector T cells. This method shows promise for the use of multi-cycle chemo-immunotherapy in the treatment of unresectable metastases of colorectal cancer in humans.